Celiac Disease Test
Medical Testing for Celiac Disease
Testing for celiac disease is an essential step in determining the proper course of treatment since this disorder can mimic so many other health conditions. There are a number of tests that can be used together to reach a definitive diagnosis.
Initial Genetic Test for Celiac Disease
Genetic screening can determine whether an individual has the gene markers DQ2 or DQ8 that make them susceptible to celiac disease. A positive result on the genetic test does not confirm that a patient has CD. However, a negative result confirms that a patient does not have CD—their symptoms are due to some other condition. This test can be particularly useful for patients with a family history of celiac disease, because they are at high risk for being affected by the same disorder themselves.
Blood Tests for Celiac
Blood tests for anti-tissue transglutaminase antibodies (tTGA) or anti-endomysium antibodies (EMA) can be used separately or in combination to determine if a patient is having an abnormal immune response that indicates celiac disease. An antibody celiac disease test is only accurate if the body is currently responding to gluten. This means the test may deliver a false negative for patients who have already reduced or eliminated gluten exposure.
Intestinal Biopsy for CD
This is the most accurate and conclusive test for celiac disease. It reveals the direct impact of gluten exposure in the intestines, where the lining is damaged. An endoscope (a tube that is fed through the throat all the way down to the lower intestine) is used to take the tissue samples. An eso-pill (a small camera that can be swallowed) is a less invasive way to visualize the intestine and check for signs of inflammation.
The Saliva Celiac Test
Testing saliva for antibodies is a newer option for CD patients. An initial trial with 5,000 children in Italy demonstrated an accuracy rate of about 90% (when results were confirmed with blood tests and intestinal biopsy). Since this test is non-invasive, it may serve as a first step in diagnosing celiac disease. However, finding a lab in the United States that provides this test may prove challenging. It is not currently a common form of testing for celiac disease.
Patients may need to be proactive in requesting these tests if they suspect they have celiac. Misdiagnosis is still common because many doctors do not know how to test for celiac disease—or because they simply don’t think to check for it.